and images of exotic, high-performance race cars may spring to mind. While a turbocharger
can deliver impressive, high-end engine performance and acceleration (as in the
world-class WRX), it also can improve the everyday, around-town performance of almost
any vehicle while still providing efficient, economical operation.

An internal-combustion engine requires both fuel (such as gasoline) and air to operate.
An engines performance is directly related to how much fuel and air it can
take in and combust in its cylinders during operation  the greater the amount
of air and fuel, the greater the engines performance.

A centrifugal turbocharger (turbo
for short) increases the power of an internal-combustion engine by pumping air into
its combustion chambers at higher-than-normal pressures.
A turbocharger forces air into the engines intake manifold. This creates a
denser air/fuel mixture, resulting in higher engine power output. With a turbocharger,
a smaller engine can provide the power of a larger engine without sacrificing efficiency,
size, or weight. Best of all, a turbocharger doesnt use any engine power to
operate  its powered by the engines exhaust gasses, which would
normally go to waste.

A turbocharger unit contains two fans. The fans are encased in separate chambers,
but are mounted on opposite ends of a common shaft. The engine exhaust flows through
one of the chambers past one of the fans (called the
turbine), causing it to turn and rotate the shaft. The second fan on
the opposite side of the shaft (called the compressor)
is in a chamber mounted in the engines intake system. When the second fan
turns, it compresses the air entering the engines air intake manifold. This
boost of intake air works to improve the engines performance.

An intercooler system is often used when
a turbocharger is installed on an engine. An intercooler cools the air compressed
by the turbocharger before it enters the intake manifold. Why? As the incoming air
is compressed by the turbocharger, its temperature increases, making it less dense
and less effective for combustion. Mounted between the turbocharger and the intake
manifold, the intercooler  essentially a small radiator  removes the
heat from the air, increasing its density and improving its effectiveness before
combustion.

The amount of turbocharger boost thats delivered to the engine is regulated
by the systems wastegate. When the
desired level of turbo boost is reached, the wastegate bypasses excess exhaust gasses
around the turbine wheel. The wastegates operation is controlled electronically
by the vehicles engine control module (ECM).

In the early 1980s when turbochargers started to become commonplace on production
passenger cars, drivers often complained of a lack of turbocharger response at low
speeds  a condition referred to as turbo lag.
At low speeds, an engine produces very little exhaust gas, and consequently the
turbocharger has very little to power it. When drivers stepped on the accelerator,
it would take a few seconds for the increasing exhaust gasses to spool up
the turbocharger to the point where it would produce a noticeable amount of power.
Engineers have essentially eliminated turbo lag through improved turbocharger design
and the use of more effective computer-controlled engine management systems. The
lopsided, all-or-nothing performance once provided by turbochargers is a thing of
the past. Current turbocharging systems are carefully tailored to provide smooth
power delivery and lower exhaust emissions at all engine operating speeds and driving
conditions. Its an effective, efficient way to improve your vehicles
performance.

Both turbochargers
and superchargers compress air entering an engines intake manifold to help
increase power. While a turbocharger is powered by the energy in the engines
exhaust stream, a supercharger is directly connected to the engines crankshaft
via a belt, chain, or gears. With this direct connection to the engine, a supercharger
requires the engine to work a little harder, and consequently, use more fuel. The
increased engine output the supercharger provides makes up for the extra power it
requires, but essentially superchargers are less efficient than turbochargers.

* Manufacturer's suggested retail price does not include destination and delivery charges, tax, title and registration fees. Destination and delivery includes handling and inland freight fees and may vary in some states. Prices, specifications, options, features and models subject to change without notice.

** EPA-estimated fuel economy. Actual mileage may vary.

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